civic dx 93 won't start

Thanks txgreasemonkey,

I removed the rust from the ground connection (G101) near the thermostat, applied wd-40. The engine started at 2nd attempt, but was stumbling...I gave some gas to keep it running but as soon as I released the accelerator, the engine stalled. I get a reading of 3.5V at the MAP connection now. I get no continuity between pins D19 and D20. What is an 'open'?

I checked the ICM according to the Honda shop manual and voltage values seem right so the ICM seems OK. Couldn't check the Coil because I stripped one screw that has top be removed to perform the test. Got any trick on how I can remove the screw? Should I replace the whole distributor instead?

You think the ECM is fine then?

Thanks

Yes, it does go out + there is no code stored in the ECM

Hi txgreasemonkey, in fact I did not ruin the threads of Terminal B but rather the spot where you put the screwdriver point...so I can't remove the screw now. I'm not sure what to do: try to unscrew with pliers or simply drill the screw until it's gone? Any Idea? Let's say the coil is OK, is there a procedure to check the distributor's internal sensors (CYL, CYK, and TDC).

My civic is about 240 000 km = 150 000 miles. I bought it about 3 years ago for peanuts. The previous owner had the car for 10 years when the engine blew up without notice. We got a used engine under the hood, a new starter, new water pump, new radiator, new timing belt and I think a new distributor (not sure).

I measured voltage again at the MAP connector and got 3.5V grounding at the connector or at G101 near the thermostat. Now finding the open along the D19 YEL/GRN (+) won't be easy..have you got any trick? Do I have to look for a crack in the wire insulation or a break in the copper wire itself? Do I have to cut the wire and replace with a new one?

Now, I've got some interesting facts. My Civic started this evening after the sun came down. The last 7 days have been pretty hot and humid, with daytime temperatures going above 86 degrees F. Conditions changed overnight and today was cool and dry, temperature was about 77 degrees F. The engine started the first time I turned the key. It ran OK but I noticed it seemed to vibrate a bit and seemed to misfire lightly when pushing the throttle. I let the engine run for 5 minutes then stopped it. I turned it on again but this time the engine started and stopped soon after. I tried again for a third time and the engine started and ran almost normally except for some vibration. I haven't checked the main relay as I hear the clicks when I turn the key to on and when I start the engine. You think this could be involved?

I'll try to check the main relay tomorrow to find out. Even though the distributor was changed not too long ago, it might well be the culprit as they have a lousy reputation. I'll try to test the other components in the distributor. Could also be the ECM. My previous car, a Mazda proteg 1991, would start but run like **** with lots of misfiring and stumbling on acceleration because of corrosion in the ECM. I'm not sure what to try as I want to avoid unnecessary costs.

Thanks

Forgot to mention I changed the fuel filter, the spark plugs, the air filter, the rotor and distributor cap about 3 months ago. The spark plug wires test fine (below 25 ohms of resistance).

Yes I did put some wd-40 on the D harness. I'll try putting some on the MAP sensor connector

Try a small pair of visegrips or pliers just to break the screw loose. Sears sells "easy out" type of tools but, if you are careful, you can probably free it.

Did you perform the other voltage tests on the MAP sensor connector?

I tested voltage between the YEL/GRN (+) reference (right) D19 and the GRN/BLU (-) neutral (middle) D21 wire and got 3.5V.

I'll have to try testing the what (+) signal (left) D17 wire and the the GRN/BLU (-) neutral (middle) D21 wire.

I don't suspect the CYK, CYL, or TDC sensors as being part of your problem. I still suspect it has something to do with the drop in voltage between the ECM and the MAP sensor connector. Make sure G101 is as clean as you can get it and run resistance tests between the ECM connector and the MAP sensor connector. I'm not sure I can help you pinpoint it any more than that--just use your common sense. You really need approximately 5 volts and you are only getting 3.5 volts. Keep in mind that the ECM and the MAP sensor work together to control timing and air/fuel mixture. These are tough and frustrating problems; however, you learn so much from them and the victory, when it comes, is huge.

Remember to check your main relay. Fluctuating performance, based on temperature changes, is characteristic of failing main relays. There are only a handful of components to realistically consider: ECM, main relay, MAP sensor, ICM, and coil.